STUDY OF THE REQUIRED HLB FOR THE SOLUBILIZATION OF CHOLESTEROL IN AQUEOUS-SOLUTION

The solubilization of cholesterol by anionic surfactant mixtures was s tudied as a function of their HLB values. The relationship between the logarithm of the critical micelle concentration and the HLB value of the mixtures was not linear, which was attributed to a lack of strict additivity of the HLB values. The solubilized cholesterol/surfactant r atio was determined and it was found to be higher than that in bile sa lts in all the studied surfactant mixtures. Below HLB = 24, emulsions were obtained, and the remaining cholesterol was solid. Above that val ue, limpid solutions were obtained, giving a solubility maximum at HLB approximate to 35. The non-solubilized cholesterol was mainly in the form of lamellar mesophase.